Perovskite precursor solution, perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite precursor solution, a perovskite solar cell and a preparation method thereof, the perovskite precursor solution comprises a solute, a 1-methylisatin additive and an organic solvent, the solute comprises methylamine halide plumbate and / or formamidine halide plumbate, and hydrogen bonds and coordination are formed between the 1-methylisatin additive and the solute. According to the invention, a 1-methylisatin additive is introduced into a perovskite precursor solution, 1-methylisatin molecules and components of the precursor solution generate coordination and hydrogen-bond interaction, and two C = O on the molecular structure of the 1-methylisatin can generate stronger interaction with lead ions in the solution, so that the crystallization process of the film is regulated and controlled; the quality and the stability of the perovskite thin film are improved, and the performance of a photoelectric device is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite precursor solution, a perovskite solar cell and a preparation method thereof. Background Art

[0002] As an emerging optoelectronic semiconductor material, perovskite materials have attracted widespread attention in the field of solar cells in recent years due to their excellent light absorption characteristics, high photoelectric conversion efficiency, and low-cost preparation process. However, the crystallization process of perovskite materials has a crucial influence on the quality of their films and the performance of the final devices. The perovskite crystallization process is easily affected by factors such as environmental humidity, solvent evaporation rate, and temperature, which can lead to problems such as uneven film quality, high porosity, or incomplete crystallization. These problems directly affect the optoelectronic properties and stability of perovskite films, limiting their widespread promotion in practical applications. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, embodiments of the present invention provide a perovskite precursor solution, a perovskite solar cell and a method for preparing the same.

[0005] In a first aspect, the present invention provides a perovskite precursor solution, comprising:

[0006] a solute, wherein the solute comprises methylamine halide plumbate and / or formamidine halide plumbate;

[0007] 1-methyl isatin additive, wherein the 1-methyl isatin additive forms hydrogen bonds and coordination with the solute;

[0008] Organic solvents.

[0009] Furthermore, the halogen element in the solute is one or more of chlorine, bromine and iodine.

[0010] Furthermore, the addition amount of the 1-methyl isatin additive is 0.01 to 10 mg / ml.

[0011] Furthermore, the organic solvent includes one or more of DMF, DMSO, NMP and GBL.

[0012] In a second aspect, the present invention proposes a perovskite solar cell, comprising a conductive substrate, a transparent conductive oxide layer, a hole transport layer, a perovskite light absorbing layer, an electron transport layer, and a back electrode stacked in sequence, wherein the perovskite light absorbing layer is prepared from the perovskite precursor solution proposed in the first aspect above.

[0013] Furthermore, the thickness of the perovskite light-absorbing layer is 300-600 nm.

[0014] In a third aspect, the present invention provides a method for preparing a perovskite solar cell according to the second aspect, comprising the following steps:

[0015] (a) Prepare a clean and dry conductive substrate;

[0016] (b) forming a transparent conductive oxide layer on the surface of the conductive substrate;

[0017] (c) forming a hole transport layer on the surface of the transparent conductive oxide layer;

[0018] (d) forming a perovskite light absorbing layer on the surface of the hole transport layer;

[0019] (e) forming an electron transport layer on the surface of the perovskite light absorbing layer;

[0020] (f) forming a back electrode on the surface of the electron transport layer.

[0021] Further, the step (d) comprises:

[0022] (1) coating a precursor solution on the surface of the hole transport layer;

[0023] (2) placing the hole transport layer obtained in step (1) on a heating platform and annealing it in an inert gas atmosphere to obtain a perovskite film.

[0024] Furthermore, the coating method in step (2) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slit extrusion coating.

[0025] Furthermore, in the step (2), the annealing temperature is 100 to 300° C., and the annealing time is 10 to 60 minutes.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The present invention introduces a 1-methyl indigo carmine additive into a perovskite precursor solution. The 1-methyl indigo carmine molecules produce coordination and hydrogen bonding effects with the components of the precursor solution. The two C=O groups in the 1-methyl indigo carmine molecular structure can produce a stronger interaction with the lead ions in the solution, thereby regulating the crystallization process of the film, improving the quality and stability of the perovskite film, and further improving the performance of the optoelectronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0029] Figure 1The present invention is a flow chart of the method for preparing a perovskite solar cell;

[0030] Figure 2 1-methyl isatin additive of the present invention. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0032] The perovskite precursor solution, perovskite solar cell and preparation method thereof of the present invention are described below with reference to the accompanying drawings.

[0033] The perovskite precursor solution includes a solute, a 1-methyl isatin additive and an organic solvent, wherein the solute includes methylamine halide lead salt and / or methylammonium halide lead salt, the halogen element in the solute is one or more of chlorine, bromine and iodine, and the organic solvent includes one or more of DMF (dimethylformamide), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone) and GBL (1,4-butyrolactone).

[0034] The structural formula of 1-methyl isatin additive is as follows Figure 2 As shown, the 1-methyl indigo carmine molecule has a structure similar to NMP, a commonly used solvent for perovskites, and can therefore produce coordination and hydrogen bonding with the components of the precursor solution. In addition, the two C=O groups in the molecular structure can produce stronger interactions with the lead ions in the solution, thereby regulating the crystallization process of the film.

[0035] The amount of 1-methyl isatin additive added is 0.01-10 mg / ml. In some embodiments, the amount of DDS additive added can be 5%, 6%, 7%, 8%, 9%, 10% of the solute mass, or a value within the range of any two values.

[0036] When the amount of 1-methyl indigo carmine additive added is within an appropriate range, the perovskite crystallization is improved and defects are passivated; when the amount of 1-methyl indigo carmine additive added is too much, the perovskite film crystallization is hindered and the grains are not dense; when the amount of 1-methyl indigo carmine additive added is too little, the defect passivation effect is not obvious and the battery performance improvement is low.

[0037] Methods for preparing perovskite solar cells, such as Figure 1 As shown, using a perovskite precursor solution, the following steps are included:

[0038] (a) Prepare a clean and dry conductive substrate;

[0039] (b) forming a transparent conductive oxide layer on the surface of the conductive substrate;

[0040] (c) forming a hole transport layer on the surface of the transparent conductive oxide layer;

[0041] (d) forming a perovskite light absorbing layer on the surface of the hole transport layer;

[0042] (e) forming an electron transport layer on the surface of the perovskite light absorbing layer;

[0043] (f) forming a back electrode on the surface of the electron transport layer.

[0044] The step (d) comprises:

[0045] (1) coating a precursor solution on the surface of the hole transport layer;

[0046] (2) placing the hole transport layer obtained in step (1) on a heating platform and annealing it in an inert gas atmosphere to obtain a perovskite film.

[0047] The coating method in step (2) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slot extrusion coating. The annealing temperature in step (2) is 100-300° C., and the annealing time is 10-60 min. In addition, the thickness of the perovskite film is controlled by the concentration of the perovskite precursor solution and the coating thickness.

[0048] The present invention is described below in conjunction with specific examples. The test materials and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0049] Example 1

[0050] Preparation of perovskite precursor solution:

[0051] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 0.6 mg 1-methyl indigo carmine were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 ml DMSO to prepare a perovskite precursor solution with a molar concentration of 1.47 mol / L for later use.

[0052] Preparation of solar cells:

[0053] The conductive substrate is cleaned and a transparent oxide is deposited on its surface to form an ITO conductive substrate with a thickness of 20 nm. A NiOx hole transport layer is formed on the surface of the ITO conductive substrate by magnetron sputtering, and the thickness of the NiOx hole transport layer is 20 nm. The precursor solution is spin-coated on the surface of the hole transport layer to form a perovskite film with a thickness of 600 nm. The obtained perovskite film is annealed at a temperature of 150°C for a treatment time of 40 min. An electron transport layer is evaporated on the surface of the perovskite film by thermal evaporation. The electron transport layer includes a fullerene layer and a barrier layer. A 20 nm C60 fullerene layer is first evaporated on the surface of the perovskite film, and then a 20 nm thick SnO2 barrier layer is prepared by atomic layer deposition. A 150 nm Ag back electrode is evaporated on the surface of the electron transport layer by thermal evaporation.

[0054] Example 2

[0055] Preparation of perovskite precursor solution:

[0056] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 5 mg 1-methyl indigo carmine were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 ml DMSO to prepare a perovskite precursor solution with a molar concentration of 1.47 mol / L for later use.

[0057] Preparation of solar cells:

[0058] The conductive substrate is cleaned and a transparent oxide is deposited on its surface to form an ITO conductive substrate with a thickness of 20 nm. A NiOx hole transport layer is formed on the surface of the ITO conductive substrate by magnetron sputtering, and the thickness of the NiOx hole transport layer is 20 nm. The precursor solution is spin-coated on the surface of the hole transport layer to form a perovskite film with a thickness of 600 nm. The obtained perovskite film is annealed at a temperature of 150°C for a treatment time of 40 min. An electron transport layer is evaporated on the surface of the perovskite film by thermal evaporation. The electron transport layer includes a fullerene layer and a barrier layer. A 20 nm C60 fullerene layer is first evaporated on the surface of the perovskite film, and then a 20 nm thick SnO2 barrier layer is prepared by atomic layer deposition. A 150 nm Ag back electrode is evaporated on the surface of the electron transport layer by thermal evaporation.

[0059] Example 3

[0060] Preparation of perovskite precursor solution:

[0061] 240.8 mg FAI, 737.6 mg PbI2, 18.2 mg CsI, 33.8 mg MACl and 10 mg 1-methyl indigo carmine were dissolved in a mixed solvent of 0.8 mL DMF and 0.2 ml DMSO to prepare a perovskite precursor solution with a molar concentration of 1.47 mol / L for later use.

[0062] Preparation of solar cells:

[0063] The conductive substrate is cleaned and a transparent oxide is deposited on its surface to form an ITO conductive substrate with a thickness of 20 nm. A NiOx hole transport layer is formed on the surface of the ITO conductive substrate by magnetron sputtering, and the thickness of the NiOx hole transport layer is 20 nm. The precursor solution is spin-coated on the surface of the hole transport layer to form a perovskite film with a thickness of 600 nm. The obtained perovskite film is annealed at a temperature of 150°C for a treatment time of 40 min. An electron transport layer is evaporated on the surface of the perovskite film by thermal evaporation. The electron transport layer includes a fullerene layer and a barrier layer. A 20 nm C60 fullerene layer is first evaporated on the surface of the perovskite film, and then a 20 nm thick SnO2 barrier layer is prepared by atomic layer deposition. A 150 nm Ag back electrode is evaporated on the surface of the electron transport layer by thermal evaporation.

[0064] Comparative Example 1

[0065] The difference from Example 1 is that when preparing the perovskite precursor solution, no 1-methyl isatin additive is added.

[0066] Comparative Example 2

[0067] The difference from Example 1 is that when preparing the perovskite precursor solution, the amount of 1-methyl indigo carmine additive added is 12 mg.

[0068] Test example

[0069] The perovskite solar cells prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were tested by a solar light simulator to test the photoelectric conversion efficiency of the perovskite solar cells. The test results are shown in Table 1 below.

[0070] Table 1

[0071] Grouping Photoelectric conversion efficiency Example 1 20.2％ Example 2 21.68％ Example 3 20.45％ Comparative Example 1 17.32％ Comparative Example 2 18.46％

[0072] According to Table 1, adding 1-methyl indigo carmine additive can significantly improve the conversion efficiency of solar cells. When no 1-methyl indigo carmine additive is added or the amount of 1-methyl indigo carmine additive added is too much, it is not conducive to improving the conversion efficiency of solar cells.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A perovskite precursor solution, characterized in that: include: a solute, wherein the solute comprises methylamine halide plumbate and / or formamidine halide plumbate; 1-methyl isatin additive, wherein the 1-methyl isatin additive forms hydrogen bonds and coordination with the solute; Organic solvents.

2. The perovskite precursor solution according to claim 1, characterized in that The halogen element in the solute is one or more of chlorine, bromine and iodine.

3. The perovskite precursor solution according to claim 1, characterized in that The added amount of the 1-methyl isatin additive is 0.01 to 10 mg / ml.

4. The perovskite precursor solution according to claim 1, characterized in that The organic solvent includes one or more of DMF, DMSO, NMP and GBL.

5. A perovskite solar cell, characterized in that: It comprises a conductive substrate, a transparent conductive oxide layer, a hole transport layer, a perovskite light absorbing layer, an electron transport layer and a back electrode which are stacked in sequence, wherein the perovskite light absorbing layer is prepared from the perovskite precursor solution according to any one of claims 1 to 4.

6. The perovskite solar cell according to claim 5, characterized in that The thickness of the perovskite light-absorbing layer is 300-600 nm.

7. A method for preparing a perovskite solar cell, characterized in that: The method for preparing the perovskite solar cell according to claim 5 or 6 comprises the following steps: (a) Prepare a clean and dry conductive substrate; (b) forming a transparent conductive oxide layer on the surface of the conductive substrate; (c) forming a hole transport layer on the surface of the transparent conductive oxide layer; (d) forming a perovskite light absorbing layer on the surface of the hole transport layer; (e) forming an electron transport layer on the surface of the perovskite light absorbing layer; (f) forming a back electrode on the surface of the electron transport layer.

8. The preparation method according to claim 7, characterized in that: The step (d) comprises: (1) coating a precursor solution on the surface of the hole transport layer; (2) placing the hole transport layer obtained in step (1) on a heating platform and annealing it in an inert gas atmosphere to obtain a perovskite film.

9. The preparation method according to claim 8, characterized in that: The coating method in step (2) includes one of spin coating, spray coating, blade coating, screen printing, air knife coating, and slit extrusion coating.

10. The preparation method according to claim 8, characterized in that: In the step (2), the annealing temperature is 100 to 300° C., and the annealing time is 10 to 60 minutes.

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